Question

Identify reductant in following reaction: $\text{C}_2\text{O}_4^{2-} + \text{MnO}_4^- + \text{H}^+ \longrightarrow \text{Mn}^{2+} + \text{CO}_2 + \text{H}_2\text{O}$

• A. $\text{H}^+$
• B. $\text{H}_2\text{O}$
• C. $\text{C}_2\text{O}_4^{2-}$
• D. $\text{MnO}_4^-$

Hint:

Look for the element that is gaining oxygen links or shedding electrons! Carbon moves from a crowded $+3$ oxalate state to a fully oxidized $+4$ dioxide state, signaling a classic oxidation process that defines a reducing agent.

Answer 1

The Correct Option is C

Step 1: Define reductant.
The reductant is the species that is oxidised, meaning its oxidation number goes up as it loses electrons.

Step 2: Track oxidation numbers.
Manganese in $MnO_4^-$ is +7 and drops to +2, so permanganate is reduced. Carbon in oxalate is +3 and rises to +4 in $CO_2$, so oxalate is oxidised.

Step 3: Pick the reductant.
The oxalate ion loses electrons, so it is the reductant.
\[ \boxed{C_2O_4^{2-},\ \text{option 3}} \]